I just got refunded by WCW because of their hose. Mine never dropped below 5PPM, even after a hour of running. Replaced it with Gardiner’s hose, which was £20 or so more expensive but totally worth it, read 0ppm from the word go!
I will say, I didn’t use my system for about a week and it needed flushing out, but not for 5 minutes.

I have my bank details printed on my "Windows Cleaned' cards and also include them in reminder texts I send to customers. I have customers say cash and then pay by bank cause the details are on the card. I only offer cash now as a on the day, at the job option.

I’ve had clients not sure about WFP because of cowboys in the past. They decided to ‘give it a go’ and now they're as happy as larry. Don’t let a customer tell you how to do your job, trad or WFP.
Edit: I will say, I would probably make a exception for a ground floor flat/bungalow that’s willing to pay big money, as I’m trading without risk.

Pfft, I’ve been window cleaning for 4 months, what do I know? I just know it’s worked really well for me and I’ve had next to no complaints (one moody person who couldn’t give me specifics, and one guy who complained of spotting but that was my fault, my PPM was too high). It was the brush I was told to get starting out and not knowing anything I did. So I can recommend it.
What are you thinking of getting in terms of jets? I’ve got pencils in the flocked and they work well, but just got 100° fans in my new brush and they’re awesome!

Newbie or pro, it’s a great thing to have. If you haven’t made your order yet then defo add it.
Just for reference, my first brush was the Ultimate Flocked. Found it great! Got a Xtreme Medium Hybrid now for regular work and keeping the flocked for first cleans, frames etc.

We would give you direction. I built mine a few months ago and thus all the parts should still be available. Honestly, but quality and you won’t regret it. Here’s what I built. I can even PM you instructions and links to the different parts. You don’t need to build it with the reel to keep costs down, if you wish.
Yes, it is going to cost you more, but what you posted isn’t everything you need anyway. You still need a DI Vessel and resin, plus extra containers.

Probably too late for this order but if your ordering again get one or two of these.
http://gardinerpolesystems.co.uk/all-products/water-fed-poles/brushes/brush-head-attachments/super-litear-brush-bumper.html
I needed it heat mine up to fit it, mind. Will help minimise any potential damage.